Improve Broker‘s startup script for Accurate Memory Allocation (#210)

This update prevents Out-Of-Memory (OOM) errors in  Broker's pods by accurately adhering to their allocated memory, rather than relying on the host's total memory.

Author: MrLYG

images/broker/alpine/runbroker-customize.sh

@@ -55,7 +55,34 @@ calculate_heap_sizes()
     case "`uname`" in
         Linux)
             system_memory_in_mb=`free -m| sed -n '2p' | awk '{print $2}'`
+            if [ -f /sys/fs/cgroup/memory/memory.limit_in_bytes ]; then
+                system_memory_in_mb_in_docker=$(($(cat /sys/fs/cgroup/memory/memory.limit_in_bytes)/1024/1024))
+            elif [ -f /sys/fs/cgroup/memory.max ]; then
+                system_memory_in_mb_in_docker=$(($(cat /sys/fs/cgroup/memory.max)/1024/1024))
+            else
+                error_exit "Can not get memory, please check cgroup"
+            fi
+            if [ $system_memory_in_mb_in_docker -lt $system_memory_in_mb ];then
+              system_memory_in_mb=$system_memory_in_mb_in_docker
+            fi
+
             system_cpu_cores=`egrep -c 'processor([[:space:]]+):.*' /proc/cpuinfo`
+            if [ -f /sys/fs/cgroup/cpu/cpu.cfs_quota_us ]; then
+                system_cpu_cores_in_docker=$(($(cat /sys/fs/cgroup/cpu/cpu.cfs_quota_us)/$(cat /sys/fs/cgroup/cpu/cpu.cfs_period_us)))
+            elif [ -f /sys/fs/cgroup/cpu.max ]; then
+                QUOTA=$(cut -d ' ' -f 1 /sys/fs/cgroup/cpu.max)
+                PERIOD=$(cut -d ' ' -f 2 /sys/fs/cgroup/cpu.max)
+                if [ "$QUOTA" == "max" ]; then # no limit, see https://docs.kernel.org/admin-guide/cgroup-v2.html#cgroup-v2-cpu
+                  system_cpu_cores_in_docker=$system_cpu_cores
+                else
+                  system_cpu_cores_in_docker=$(($QUOTA/$PERIOD))
+                fi
+            else
+                error_exit "Can not get cpu, please check cgroup"
+            fi
+            if [ $system_cpu_cores_in_docker -lt $system_cpu_cores -a $system_cpu_cores_in_docker -ne 0 ];then
+              system_cpu_cores=$system_cpu_cores_in_docker
+            fi
         ;;
         FreeBSD)
             system_memory_in_bytes=`sysctl hw.physmem | awk '{print $2}'`